The invention relates to an arrangement for detecting dielectric breakdowns in metal-clad, high-voltage switching and transmission systems equipped with several gastight compartmentalized sections. The detecting arrangement determines the faulty section with at least one stationary measuring device.
A compressed-gas-insulated high-voltage switching installation with an arrangement for monitoring the gas pressure is described in the journal Revue Generale De L'Electricite, April 1966, at pages 493 to 500; this arrangement causes the system to shut down at pressures higher than the operating pressure. Here, however, the danger to the system caused by the occurrence of a fault cannot be determined with more accuracy, than to distinguish, for instance, between an increase in pressure because of a temperature change caused by heating as a consequence of normal load or, as a consequence of a fault arc.
In the Deutsche Offenlegungsschrift 1,665,637 a compressed gas-insulated high-voltage switching installation is described which includes an arrangement for monitoring the gas pressure and causes the system to shut down at pressures higher than the operating pressure. As the criterion for switching the system off, the rate of change of the gas pressure is taken into consideration here. In this manner, normal operation can be distinguished from fault situations after the monitoring device has responded.
In both known arrangements, direct access to the interior of the installation must be provided so that the pressure prevailing there can be fed to the measuring device, for example, a pressure transducer. Equipping an already existing high-voltage switching and transmission installation is very expensive because of the work required to empty and fill the encapsulation and because of the installation of the measuring device in a gastight manner.